In Baghdad, at least two women were killed by several armed men who fired at a car, a security official said. Their driver was also wounded.
The women had reportedly worked for the Iraqna mobile phone company.
Also in Baghdad, at least three people were killed in a roadside bombing and 13 others wounded, including Maytham Ibrahim, a cameraman working for the Al-Diyar satellite television network.
The bomb exploded in the eastern neighbourhood of Talbiyah. Basra violence
A roadside bomb exploded near a convoy carrying Iraqi generals in the southern city of Basra.
The city's security chief was in the car when the blast went off in a neighbourhood that is a stronghold for the Mahdi Army
There were no major injuries reported.
The blast comes after Nuri al-Maliki, Iraq's prime minister, hailed a week-long military assault against Shia fighters in Basra as a "success". Call for release
Meanwhile, Reporters Without Borders (RWB), a Paris-based media monitoring group, has called for the release of Ahmed Mahmud Hassan, a journalist for Al-Sumariya satellite television channel.
The organisation claims that Hassan was arrested on March 30 in Mahmudiyah, 30km south of Baghdad, "while covering clashes between Iraqi forces and rebel insurgents".
The journalist is thought to be detained at a military base, RWB has said.
According to the Iraqi Journalists Freedom Observatory (JFO), which monitors violence against the media, 233 Iraqi and foreign journalists and media workers have been killed in Iraq since the US-led invasion of March 2003.